Uranus



What is a planet ?
A planet is a body that orbits the Sun, or another star, and produces no light of ts own, but reflects light off of the Sun.

What Is Uranus ?
It is the 7th planet in our solar system and the 3rd largest gas giant. It is the only planet that spins on its side. It is pale blue-green
with a cloudy atmosphere. It is also half the size of Saturn and four times the size of Earth. Despite Neptune being the furthest, Uranus
is the coldest planet in the solar system. Uranus is named for the Greek god of the sky. It has 27 known satellites (or moons) and 11 rings.
It is the first planet to be discovered in modern history.

Uranus.jpg
a view of uranus



Uranus: A Strange Planet
Uranus was discovered in 1781 by William Herschel. When William Herschel died at the age of 84, Uranus was in the same place in the
sky it had been when he was born. At some point in history, Uranus was struck by an object knocking it to its side. Its equator lies on a plane
perpendicular to the plane of the other planets' orbits. It has blue-greenish color because the atmospheric methane absorbs the light at the
red end of a visible spectrum and reflects light at the blue end. The winds blow in the direction of the planet's rotation at velocities of 40 to 160 per
second (90 to 360 miles per hour). Uranus rotates every 17 hours and 14 minutes which makes its day shorter than an Earth day.
Its average distance from the sun is about 1,784,860,000 miles (2,872,460,000 kilometers), a distance that takes light 2 hours and 14 minutes to travel.
Uranus takes 30,685 Earth days to complete an orbit around the Sun. A Uranian year = 84 Earth days.




27 Moons and 11 Rings


Uranus has at least 27 known satellites. They are named after Shakespearean characters. The five largest moons are: Titania, Oberon, Umbriel, Ariel and Miranda.
Miranda is the strangest because it has a curious mix of surface features. It is believed to be half rocky, with deep grooves etched into its surface. Ariel is the brightest at magnitude 14. Oberon and Titania were the first to be discovered by William Herschel in 1781. The Voyager 2 visited the Uranian planet in 1986 and found an additional 10 and tripled the number of moons, bringing it to a total of 27 satellites. Uranus has 11 rings. The rings are made of black chunks of rock and ice. The brightest ring is called epsilon.


external image Uranus_moons.jpgexternal image 11_05b.jpg

Five Largest Moons & Position of Uranus' Moons

All of Uranus's inner moons (those observed by Voyager 2) appear to be roughly half water ice and half rock. The composition of the moons outside the orbit of Oberon remains unknown, but they are likely captured asteroids.
Miranda, the innermost and smallest of the five major satellites, has a surface unlike any other moon that's been seen. It has giant fault canyons as much as 12 times as deep as the Grand Canyon, terraced layers, surfaces that appear very old, and others that look much younger.
Ariel has the brightest and possibly the youngest surface among all the moons of Uranus. It has few large craters and many small ones, indicating that fairly recent low-impact collisions wiped out the large craters that would have been left by much earlier, bigger strikes. Intersecting valleys pitted with craters scars its surface.
Umbriel is ancient, and the darkest of the five large moons. It has many old, large craters and sports a mysterious bright ring on one side.
Oberon, outermost of the five major moons, is old, heavily cratered, and shows little signs of internal activity. Unidentified dark material appears on the floors of many craters.
Cordelia and Ophelia are shepherd moons that keep Uranus' thin, outermost "epsilon" ring well defined.

Uranus's Moons:
external image uranus_ring_moons.jpg
external image uranus_ring_moons.jpg

  1. Cordelia
  2. Ophelia
  3. Bianca
  4. Cressida
  5. Desdemona
  6. Juliet
  7. Portia
  8. Rosalind
  9. Mab
  10. Belinda
  11. Perdita
  12. Puck
  13. Cupid
  14. Miranda
  15. Francisco
  16. Ariel
  17. Umbriel
  18. Titania
  19. Oberon
  20. Caliban
  21. Stephana
  22. Trinculo
  23. Sycorax
  24. Margaret
  25. Prospero
  26. Setebos
  27. Ferdinand

Fun Facts
  • Its the third gas giant
  • 1 day = 42 years
  • Rotates on its side
  • Discovered by William Herschel
  • It is the mythological father of Saturn
  • Has 27 moons and 11 rings
  • Temperature of -350 degrees fahrenheit
  • 1.78 billion miles from the Sun
  • 31,800 miles in diameter
  • 83% hydrogen, 15% helium, methane
  • 17.24 hour rotation
  • 97.9 degrees is the tilt










Bibliography
  1. (Encyclopedia) - Astronomy and Space, Phillis Engelbert, Thomas L. Romig, Detroit, 1997
  2. (Book) - Uranus, Neptune, Pluto and the Outer Solar Systems, Linda T. Tanton-Elkins, Chelsea House Publishers, New York, 2006
  3. (Website) - Uranus Facts, Kelly Whitt, 2007, http://astronomyspace.suite101.com/article.cfm/uranus_facts
external image thm-uranus_symbol.jpg

NASA

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